Barrell amalgamation of precious metals.



UNITED STATES ATENT FFICE.

ERNST HEILIGENDORFER, OF OANELAS, MEXICO.

BARREL AMALGAMATION OF PRECIOUS METALS.

SPECIFICATION forming part of Letters Patent N 0. 651,506, dated June 12, 1900.

Application filed July 16, 1897- Serial No. 6441832. (N0 specimens.)

To all whom it may concern:

Be it known that LEnnsr HEILIGEND ORFER, a citizen of Germany, residing at Oanelas, Durango, Mexico, have invented an Improvement in Barrel Amalgamation of Precious Metals; and I hereby declare the following to be a full, clear, and exact description of the same.

My invention relates to an improvement in amalgamation of precious-metal-bearing ores by What is known as the barrel process; and it consists, essentially, in the employment of copper amalgam in conjunction with what are known as rebellious ores when treated by this process. For such ores as can be desilverized without roasting the processes of raw pan amalgamation and raw barrel amalgamation are to be preferred. Both proeesses,however, are but partially successful for the so-called free-milling silver combinations with sulfur, antimony, and arsenic.

Raw pan amalgamation works principally by the action of copper amalgam formed from quicksilver and precipitated blue-stone, (sulfate of copper.) Copper amalgam is more active in the work of amalgamation than pure quicksilver and metallic copper. At the same time when sulfur attacks copper amalgam it will sulfurize only the copper without damaging the quicksilver, and this protection of the quicksilver by copper amalgam is far more efficient than metallic copper in contact with quicksilver can afford; but while pan amalgamation is thus secured againstserious losses of quicksilver a great deficiency in this form of treatment is that there is no chlorination, because iron decomposes at once the copper and cuprous chlorid, and for this reason several of the silver combinations remain in the pan in the so-called rebellious condition. On the other hand, raw amalgamation in wooden tubs and barrels or in stone ves sels is aided by chlorination with copper and cuprous chlorid and will desilverize several silver combinations which resist raw pan amalgamation. The chemicals,copper,quick silver, salt, and bluestone which are used in barrel amalgamation can, however, form no copper amalgam. The amalgamation Work gamation is enabled not only to desilverize free-milling ores more perfectly, but to extend its capacity over a wider range of raw ores which up to this time have been considered rebellious for raw panamalgamation as well as for raw barrel amalgamation. An equal success is obtained in the raw barrel amalgamation of gold-bearin g sulfurets which have been treated by a roasting process.

When rebellious ores are to be amalgamated by the barrel process, they must first be roasted with or without salt, after which they can be worked by the addition of copper amalgam with perfect success.

Having thus described my invention, What I claim as new, and desire to secure by Letters Patent, is

The improvement in the process of amalgamating silver and gold ores in vessels of such material as will not decompose copper sulfate, consisting of the combination of metallic copper, quicksilver, salt, blue-stone and copper amalgam, substantially as herein described.

In Witness whereof I have hereunto set my hand.

ERNST HEILIGENDORFER.

lVitnesses LIBRADO SILVA, MANUEL OSORIO. 

